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I talked to one of the "big three" respected Subaru engine builders just last week and I had a similar question. Besides the fact that they didn't like small 2.0L displacement, I was told that the open deck block would be fine with forged internals (nice set of rods and pistons).

Wiseco forged pistons can be had for $419 which includes rings, pins etc. Eagle rods are in the $350 range. Although this particular builder said he has seen Eagle rods and they look a little rough around the edges for his taste - and for that matter he wouldn't use them. However, on a tight budget the Wiseco pistons and Eagle rods would make since on the open deck if you could build it (labor wise) inexpensilvely.

But you could still get a ver7 shortblock for around the same amount of money and be better off? And why don't they like a small displacement 2.0? I've seen plenty of sti motors make silly amounts of power and hold up to the abuse...I think it has more to do with selling a overpriced motor.

But you could still get a ver7 shortblock for around the same amount of money and be better off? And why don't they like a small displacement 2.0? I've seen plenty of sti motors make silly amounts of power and hold up to the abuse...I think it has more to do with selling a overpriced motor.

No they said that it's "lack of torque" due to not liking a 2.0L vs 2.5 and up. It didn't really have that much to do with the overall HP power goals. Even then, you would still have to wind the smaller displacement engine up higher to achieve the same power of the larger displacement. If everything being equal 'cept displacement (internals strength, boost on like turbo and supporting mods) the larger engine wins.

I have a GT30R turbo on my car I will like to boost my car up to 22 to 24 PSI of boost of possible there is no 4WD dyno down here..........

Thanks for all the response people …..
I did get a version 8 STI motor type C but it was toast no more STI motor and till late January and this is my daily driver ……..
I will be using the STI heads and STI crank shaft for the built up with Pauter rod and CP piston cosmetic head gasket and ARP head bolts....

It is not that simple as big displacement wins everything being equeal. Big displacement win if they have same RPM's. There are lots of other factors. Gross U.S., Big Iron, Rat motor, no replacement for displacement mentality.

There are lots of ovaled open decks out here. That at "stage 4" level no less. Be carefull. Going to the trouble of building a motor, do it once. Don't skimp on the block or risk doing it again.

It is not that simple as big displacement wins everything being equeal. Big displacement win if they have same RPM's. There are lots of other factors. Gross U.S., Big Iron, Rat motor, no replacement for displacement mentality.

There are lots of ovaled open decks out here. That at "stage 4" level no less. Be carefull. Going to the trouble of building a motor, do it once. Don't skimp on the block or risk doing it again.

Good luck.

Everything being equal, there is no relacement for displacement. You can't argue that - or maybe you can. Like I said above, you would need rpms to keep the power on. Concerning the "ovaled" open decks, I'm sure that they're out there. I was just stating what was told to me by the said builder.

There are lots of ovaled open decks out here. That at "stage 4" level no less. Be carefull. .

I think that is more due to people trying to get 300whp out of a turbo that is more comfortable spitting out closer to 250whp (VF30). Excessively aggressive tunes are the suck

I have spoken to a few tuners about the issue of block strength, durability, etc and it all seems to boil down to getting too greedy with a specific setup. People want WHP, but don't want lag, so they put on relatevely tiny turbos and then get the setup tuned to within an inch of its life barely to the desired power level. wrong way to do things, as evident by the ovaled open decks found "at "stage 4" no less"

I think that is more due to people trying to get 300whp out of a turbo that is more comfortable spitting out closer to 250whp (VF30). Excessively aggressive tunes are the suck

I have spoken to a few tuners about the issue of block strength, durability, etc and it all seems to boil down to getting too greedy with a specific setup. People want WHP, but don't want lag, so they put on relatevely tiny turbos and then get the setup tuned to within an inch of its life barely to the desired power level. wrong way to do things, as evident by the ovaled open decks found "at "stage 4" no less"

So jigga what WHP and PSI of boost number do you think is not greedy with my setup to your knowledge?????
Remember I have a GT30R with a parts list mention above with a safe 11.0 AFR ……..

So jigga what WHP and PSI of boost number do you think is not greedy with my setup to your knowledge?????
Remember I have a GT30R with a parts list mention above with a safe 11.0 AFR ……..

Unfortunately, those answers I don't have either.. What I do know though is that the open deck blocks won't take the 20+psi treatment that a few are giving them around here for an extended timeframe. Closed deck blocks will take the boost, but not so much the open decks due to the reason outlined above by Ebeck.

Ultimate Racing has the Stage 5 package which uses the GT30r on the stock block. When I spoke to them, they had one example on the streets for well over a year running enough whp to net 114-115 traps. Now, when I asked about boost, they mentioned that they run a max of 18psi on 94 octane gas.

When I asked why, they mentioned that it was due to stock block strength.. They were unable to give me an exact answer on how much whp is too much. All they could say is that they had zero engine failures so far on their kits, which was impressive. This leads me to believe that max whp is more in the tune than anything else.

With regard to boost, I think the way to getting good whp and durability would be in using a turbo that is efficient at low PR's. Turbos that need to be run at 23-24 psi might make power, but that kind of boost has been shown to be not too sensible with the stock block over the long term. That much boost might be totally fine on an Evo's iron block, but not on the wrx aluminum open deck block.

I would rather have something that makes the same power at perhaps 18psi of boost.

I've kinda taken this advice to heart as well, and tend to stay under 20 psi of boost on pump gas. If I want more power, I'll go bigger instead of going for more boost than I am running right now (19psi on 1820 turbo).

We know that detonation busts up ringlands and rods, but I reckon that excessive boost has its effect on the block itself.

Since I like to err on the side of caution, I would stay under 20psi of boost as a ceiling, and then enjoy whatever whp I can get at that boost with a conservative tune for pump/race gas. If for some reason more WHP is wanted, then go bigger, so that you can flow more air while maintaining the same, or lower boost pressure. I think that doing things this way will get you the whp, while not being on the verge of ovalling your combustion chambers due to excess boost and/or timing.

I have read a few threads though about the WRX stock rods letting go at somewhere around 420whp. If you have aftermarket rods, I would assume that your whp ceiling would be higher than this number.

One more thing that you need to keep in mind as well, is that these are just 2.0L engines that we are working with.... Getting over 150WHP/L on these things is really amazing as is! Just gives an idea of how highly stressed these engines are. Sure, 350-360whp might not be too impressive to some, it is when you consider that there are 5.7L V8 engines coming from the factory producing 350HP at the crank. If you made a 5.7L V8 engine make as much power/L as a 365whp 2.0L was making, it would have somewhere around 1040whp
Just my opinions... ymmv.

But you could still get a ver7 shortblock for around the same amount of money and be better off? And why don't they like a small displacement 2.0? I've seen plenty of sti motors make silly amounts of power and hold up to the abuse...I think it has more to do with selling a overpriced motor.

You're telling me you can get a ver7 shortblock for under 800 dollars?

ive been running my car day driver for over one year now i run whp345 on pump gas , and an agressive pump gas if needit of 355whp at 21psi w a green only have forged pistons and stock rods ,yeaah i know i will replace them soon they are sitting on my garage "crower rods" on vp 116 octane i run 27 psi 430 whp no problems ,i have gadiel tuning working at my tunning for several hours and its worth it i think it only depends on the tunning, this
#s where extracted on a dynojet dyno

Unfortunately, those answers I don't have either.. What I do know though is that the open deck blocks won't take the 20+psi treatment that a few are giving them around here for an extended timeframe. Closed deck blocks will take the boost, but not so much the open decks due to the reason outlined above by Ebeck.

Ultimate Racing has the Stage 5 package which uses the GT30r on the stock block. When I spoke to them, they had one example on the streets for well over a year running enough whp to net 114-115 traps. Now, when I asked about boost, they mentioned that they run a max of 18psi on 94 octane gas.

When I asked why, they mentioned that it was due to stock block strength.. They were unable to give me an exact answer on how much whp is too much. All they could say is that they had zero engine failures so far on their kits, which was impressive. This leads me to believe that max whp is more in the tune than anything else.

With regard to boost, I think the way to getting good whp and durability would be in using a turbo that is efficient at low PR's. Turbos that need to be run at 23-24 psi might make power, but that kind of boost has been shown to be not too sensible with the stock block over the long term. That much boost might be totally fine on an Evo's iron block, but not on the wrx aluminum open deck block.

I would rather have something that makes the same power at perhaps 18psi of boost.

I've kinda taken this advice to heart as well, and tend to stay under 20 psi of boost on pump gas. If I want more power, I'll go bigger instead of going for more boost than I am running right now (19psi on 1820 turbo).

We know that detonation busts up ringlands and rods, but I reckon that excessive boost has its effect on the block itself.

Since I like to err on the side of caution, I would stay under 20psi of boost as a ceiling, and then enjoy whatever whp I can get at that boost with a conservative tune for pump/race gas. If for some reason more WHP is wanted, then go bigger, so that you can flow more air while maintaining the same, or lower boost pressure. I think that doing things this way will get you the whp, while not being on the verge of ovalling your combustion chambers due to excess boost and/or timing.

I have read a few threads though about the WRX stock rods letting go at somewhere around 420whp. If you have aftermarket rods, I would assume that your whp ceiling would be higher than this number.

One more thing that you need to keep in mind as well, is that these are just 2.0L engines that we are working with.... Getting over 150WHP/L on these things is really amazing as is! Just gives an idea of how highly stressed these engines are. Sure, 350-360whp might not be too impressive to some, it is when you consider that there are 5.7L V8 engines coming from the factory producing 350HP at the crank. If you made a 5.7L V8 engine make as much power/L as a 365whp 2.0L was making, it would have somewhere around 1040whp
Just my opinions... ymmv.

slickvic, no I didn't mean to imply that. What I was getting at was for around a grand you can get a better block, good rods and pistons, is allready BUILT and all you have to do is put the heads on and install.

I see. That makes more sense because of the fact that a preassembled shortblock could be installed by your average weekend mechanic.

The only thing is if you are looking into swapping in a ver7 or 8 block or the usdm sti block for that matter, why start with a new wrx. Get an older model impreza for alot less cash and then swap in the new engine. I'm just saying that if you are looking to do a swap, why start with a new wrx.